Linux · Shell interview questions

1. A.search text for lines matching a pattern
2. B.print the first whitespace-delimited field of each line
3. C.count the number of lines in a file
4. D.find .log files modified more than 7 days ago

Answer + AI explanation with Pro

1. A.grep
2. B.cut -d: -f1 /etc/passwd
3. C.sed
4. D.awk

Answer + AI explanation with Pro

1. A.grep — count occurrences of each unique line
2. B.grep — process and extract text by fields/columns
3. C.grep — print the first whitespace-delimited field of each line
4. D.grep — search text for lines matching a pattern

Answer + AI explanation with Pro

1. A.process and extract text by fields/columns
2. B.print the first whitespace-delimited field of each line
3. C.build and run commands from standard input
4. D.find .log files modified more than 7 days ago

Answer + AI explanation with Pro

1. A.xargs
2. B.wc -l file
3. C.awk
4. D.awk '{print $1}'

Answer + AI explanation with Pro

1. A.awk — extract the first colon-delimited field (usernames)
2. B.awk — process and extract text by fields/columns
3. C.awk — find .log files modified more than 7 days ago
4. D.awk — count the number of lines in a file

Answer + AI explanation with Pro

1. A.search text for lines matching a pattern
2. B.perform stream text substitution/editing
3. C.count the number of lines in a file
4. D.process and extract text by fields/columns

Answer + AI explanation with Pro

1. A.head -n 20 file
2. B.wc -l file
3. C.sed
4. D.find / -name '*.log' -mtime +7

Answer + AI explanation with Pro

1. A.sed — perform stream text substitution/editing
2. B.sed — count the number of lines in a file
3. C.sed — replace all 'foo' with 'bar' in-place
4. D.sed — show the first 20 lines of a file

Answer + AI explanation with Pro

1. A.the exit code of the last command (0 = success)
2. B.append output to a file instead of overwriting it
3. C.runs the next command only if the previous one succeeded
4. D.redirect stderr to wherever stdout currently points

Answer + AI explanation with Pro

1. A.2>&1
2. B.$?
3. C.| (pipe)
4. D.trap

Answer + AI explanation with Pro

1. A.2>&1 — redirect stderr to wherever stdout currently points
2. B.2>&1 — append output to a file instead of overwriting it
3. C.2>&1 — runs the next command only if the previous one succeeded
4. D.2>&1 — strict bash mode: exit on error, unset vars and pipe failures

Answer + AI explanation with Pro

1. A.a bash builtin that runs code on a received signal (e.g. cleanup on EXIT)
2. B.append output to a file instead of overwriting it
3. C.the exit code of the last command (0 = success)
4. D.sends the stdout of one command to the stdin of the next

Answer + AI explanation with Pro

1. A.$?
2. B.&& operator
3. C.| (pipe)
4. D.trap

Answer + AI explanation with Pro

1. A.$? — strict bash mode: exit on error, unset vars and pipe failures
2. B.$? — redirect stderr to wherever stdout currently points
3. C.$? — the exit code of the last command (0 = success)
4. D.$? — runs the next command only if the previous one succeeded

Answer + AI explanation with Pro

1. A.the exit code of the last command (0 = success)
2. B.a bash builtin that runs code on a received signal (e.g. cleanup on EXIT)
3. C.sends the stdout of one command to the stdin of the next
4. D.append output to a file instead of overwriting it

Answer + AI explanation with Pro

1. A.>> operator
2. B.&& operator
3. C.set -euo pipefail
4. D.| (pipe)

Answer + AI explanation with Pro

1. A.>> operator — redirect stderr to wherever stdout currently points
2. B.>> operator — the exit code of the last command (0 = success)
3. C.>> operator — a bash builtin that runs code on a received signal (e.g. cleanup on EXIT)
4. D.>> operator — append output to a file instead of overwriting it

Answer + AI explanation with Pro

1. A.show the first 20 lines of a file
2. B.perform stream text substitution/editing
3. C.build and run commands from standard input
4. D.extract the first colon-delimited field (usernames)

Answer + AI explanation with Pro

1. A.find / -name '*.log' -mtime +7
2. B.wc -l file
3. C.cut -d: -f1 /etc/passwd
4. D.awk

Answer + AI explanation with Pro

1. A.cut -d: -f1 /etc/passwd — show the first 20 lines of a file
2. B.cut -d: -f1 /etc/passwd — extract the first colon-delimited field (usernames)
3. C.cut -d: -f1 /etc/passwd — count the number of lines in a file
4. D.cut -d: -f1 /etc/passwd — perform stream text substitution/editing

Answer + AI explanation with Pro

1. A.show the first 20 lines of a file
2. B.count occurrences of each unique line
3. C.extract the first colon-delimited field (usernames)
4. D.search text for lines matching a pattern

Answer + AI explanation with Pro

1. A.sed -i 's/foo/bar/g' file
2. B.wc -l file
3. C.sort | uniq -c
4. D.head -n 20 file

Answer + AI explanation with Pro

1. A.sort | uniq -c — process and extract text by fields/columns
2. B.sort | uniq -c — count occurrences of each unique line
3. C.sort | uniq -c — count the number of lines in a file
4. D.sort | uniq -c — show the first 20 lines of a file

Answer + AI explanation with Pro

1. A.process and extract text by fields/columns
2. B.count the number of lines in a file
3. C.build and run commands from standard input
4. D.find .log files modified more than 7 days ago

Answer + AI explanation with Pro

1. A.sort | uniq -c
2. B.head -n 20 file
3. C.wc -l file
4. D.cut -d: -f1 /etc/passwd

Answer + AI explanation with Pro

1. A.wc -l file — process and extract text by fields/columns
2. B.wc -l file — find .log files modified more than 7 days ago
3. C.wc -l file — print the first whitespace-delimited field of each line
4. D.wc -l file — count the number of lines in a file

Answer + AI explanation with Pro

1. A.show the first 20 lines of a file
2. B.extract the first colon-delimited field (usernames)
3. C.search text for lines matching a pattern
4. D.build and run commands from standard input

Answer + AI explanation with Pro

1. A.wc -l file
2. B.awk
3. C.head -n 20 file
4. D.sed

Answer + AI explanation with Pro

1. A.head -n 20 file — extract the first colon-delimited field (usernames)
2. B.head -n 20 file — show the first 20 lines of a file
3. C.head -n 20 file — print the first whitespace-delimited field of each line
4. D.head -n 20 file — process and extract text by fields/columns

Answer + AI explanation with Pro